A division bench of Gujarat High Court held as follows regarding the language of a High Court.

From Paras 13, 14 and 15,

13. Before we further proceed to examine the aspects of competency to assist the Court, we need to first consider on the aspect of language of the High Court. Article 343 of the Constitution of India provides for official language of the Union. Whereas, Article 348 of the Constitution of India provides for languages of Supreme Court and High Court, etc. It is hardly required to be stated that before the constitution was framed, there were constitutional debates and deliberation on various points including about language to be used in Supreme Court and High Courts. After deliberations constitutional framers have finalised Article 348 of the Constitution. The aforesaid shows that until the Parliament by law otherwise provides, all proceedings in the Supreme Court and every High Court shall be in English. Sub-Article (2) provides that the Governor of the State may with the previous consent of the President Authorise the use of Hindi language or any other language in the proceedings of the High Court having its principal seat in that State. But such would not be applicable to any judgment decree or order passed or made by such High Court.
14. The Parliament has enacted the Official Language Act, 1963 for providing languages to be used for official purpose of Union for transaction of business in Parliament under Central and State Act and also for certain purposes in the High Courts. The aforesaid shows that the President may authorise the use of Hindi or official language of the State in addition to English language for the purpose of any judgement decree or order passed or made by the High Court, but such shall be accompanied by a translation of the same in English language.
15. The aforesaid are the enabling powers, but so far as High Court of Gujarat is concerned, the learned Advocate General after verification, made a clear statement that no such order has been passed by the Governor under Article 348 (2) of the Constitution nor any order for authorisation has been passed by the President for use of Gujarati language or any other language and he further submitted that English language is already prescribed in the proceedings of the High Court and Supreme Court by Article 348 (1) of the Constitution. To say in other words, in absence of any order of the Governor under Article 348(2) of the Constitution or in absence of any authorisation under Section 7 of the Official Language Act, the language of the High Court of Gujarat as per the Constitution of India has to be English since the word used by the Constitution is “Shall be in English language”. Hence, it can be said that the language of the High Court of Gujarat shall be English unless any authorisation has been issued under Article 348(2) of the Constitution of India or under section 7 of the Official Language Act by the Governor or the President, as the case may be.

From Para 18,

18. It is hardly required to be stated that the Constitution or any provision of the Constitution will prevail over any Act or the law made by the Parliament or the Rules made by any Rule making authority. If Rule 37 is to be given effect read with the above referred constitutional provision, it would mean the memorandum of proceedings by a party may be submitted in Gujarati or in English, but if it is in Gujarati, the party may be asked to supply English translation also and if there has no financial capacity to provide English translation, Court may direct the English translation to be made by the High Court and thereafter, the matter may be considered further. If Rule 37 of the Rules is not interpreted in that manner, it would run counter to Article 348 of the Constitution.

Citations :

Other Sources :

https://indiankanoon.org/doc/178909148/

https://www.casemine.com/judgement/in/5ac5e38c4a93261a1a76788f/